1
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Sarangi S, Sharma S, Nahak SK, Panda AK. Association of CACNA1C polymorphisms (rs1006737, rs4765905, rs2007044) with schizophrenia: A meta-analysis and trial sequential analysis. Schizophr Res 2024; 274:247-256. [PMID: 39378823 DOI: 10.1016/j.schres.2024.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Revised: 08/30/2024] [Accepted: 09/27/2024] [Indexed: 10/10/2024]
Abstract
Schizophrenia is a complex neurological disorder characterized by significant impairment in the perception of reality and changes in behavior. Genetic and environmental factors influence the development of schizophrenia. CACNA1C, which encodes a subunit of a voltage-dependent calcium channel, has been associated with various neurological disorders, including schizophrenia. Several studies have been performed in different populations to explore the association of common genetic variants in the CACNA1C gene with susceptibility to the development of schizophrenia, but results remain contradictory. To draw a definitive conclusion on the association between CACNA1C polymorphisms and schizophrenia, we conducted a meta-analysis focusing on three commonly studied polymorphisms: rs1006737, rs4765905, and rs2007044. For the meta-analysis, a comprehensive literature search was performed using PubMed, Scopus, Science Direct and Google Scholar databases. Data was retrieved, and the meta-analysis was performed using CMA v4 software. The meta-analysis revealed a significant association between rs1006737 and rs2007044 and schizophrenia in the overall population, while no such association was found for rs4765905. Population-wise analysis suggested that all three polymorphisms were significantly associated with schizophrenia in the Asian population and that rs1006737 was significantly associated with schizophrenia in Europeans. We also performed a Trial Sequential Analysis (TSA), which supported our findings. Some report-based assay studies have suggested a role for these polymorphisms in schizophrenia, but further case-control studies are needed to confirm the association of rs4765905 and rs2007044 with the disorder.
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Affiliation(s)
- Surjyapratap Sarangi
- ImmGen EvSys Laboratory BT-113, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007, India; Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore 453552, India
| | - Saurav Sharma
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology, Indore 453552, India
| | - Suraj Kumar Nahak
- ImmGen EvSys Laboratory BT-113, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007, India
| | - Aditya K Panda
- ImmGen EvSys Laboratory BT-113, Department of Biotechnology, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007, India; Centre of Excellence on Bioprospecting of Ethno-pharmaceuticals of Southern Odisha (CoE-BESO), Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007, India.
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2
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Xia C, Dai W, Carreno J, Rogando A, Wu X, Simmons D, Astraea N, Dalleska NF, Fonteh AN, Vasudevan A, Arakaki X, Kloner RA. Higher sodium in older individuals or after stroke/reperfusion, but not in migraine or Alzheimer's disease - a study in different preclinical models. Sci Rep 2024; 14:21636. [PMID: 39284837 PMCID: PMC11405707 DOI: 10.1038/s41598-024-72280-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 09/05/2024] [Indexed: 09/19/2024] Open
Abstract
Sodium serves as one of the primary cations in the central nervous system, playing a crucial role in maintaining normal brain function. In this study, we investigated alterations in sodium concentrations in the brain and/or cerebrospinal fluid across multiple models, including an aging model, a stroke model, a nitroglycerin (NTG)-induced rat migraine model, a familial hemiplegic migraine type 2 (FHM2) mouse model, and a transgenic mouse model of Alzheimer's disease (AD). Our results reveal that older rats exhibited higher sodium concentrations in cerebrospinal fluid (CSF), plasma, and various brain regions compared to their younger counterparts. Additionally, findings from the stroke model demonstrated a significant increase in sodium in the ischemic/reperfused region, accompanied by a decrease in potassium and an elevated sodium/potassium ratio. However, we did not detect significant changes in sodium in the NTG-induced rat migraine model or the FHM2 mouse model. Furthermore, AD transgenic mice showed no significant differences in sodium levels compared to wild-type mice in CSF, plasma, or the hippocampus. These results underscore the nuanced regulation of sodium homeostasis in various neurological conditions and aging, providing valuable insights into potential mechanisms underlying these alterations.
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Affiliation(s)
- Chenchen Xia
- Cognition and Brain Integration Laboratory, Neurosciences Department, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Wangde Dai
- Cardiovascular Department, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Juan Carreno
- Cardiovascular Department, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Andrea Rogando
- Cognition and Brain Integration Laboratory, Neurosciences Department, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Xiaomeng Wu
- Analytical Biochemistry Core, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Darren Simmons
- Analytical Biochemistry Core, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Natalie Astraea
- Analytical Biochemistry Core, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Nathan F Dalleska
- Water and Environment Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Alfred N Fonteh
- Biomarker and Neuro-Disease Mechanism Laboratory, Neurosciences Department, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Anju Vasudevan
- Angiogenesis and Brain Development Laboratory, Department of Neurosciences, Huntington Medical Research Institutes, Pasadena, CA, USA
| | - Xianghong Arakaki
- Cognition and Brain Integration Laboratory, Neurosciences Department, Huntington Medical Research Institutes, Pasadena, CA, USA.
| | - Robert A Kloner
- Cardiovascular Department, Huntington Medical Research Institutes, Pasadena, CA, USA
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3
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Ling QH, Fu Y, Lou ZC, Yue B, Guo C, Hu X, Lu W, Hu L, Wang W, Zhang M, Yang HB, Xu L. Naphthalene Diimide-Based Metallacage as an Artificial Ion Channel for Chloride Ion Transport. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308181. [PMID: 38459671 DOI: 10.1002/advs.202308181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/06/2024] [Indexed: 03/10/2024]
Abstract
Developing synthetic molecular devices for controlling ion transmembrane transport is a promising research field in supramolecular chemistry. These artificial ion channels provide models to study ion channel diseases and have huge potential for therapeutic applications. Compared with self-assembled ion channels constructed by intermolecular weak interactions between smaller molecules or cyclic compounds, metallacage-based ion channels have well-defined structures and can exist as single components in the phospholipid bilayer. A naphthalene diimide-based artificial chloride ion channel is constructed through efficient subcomponent self-assembly and its selective ion transport activity in large unilamellar vesicles and the planar lipid bilayer membrane by fluorescence and ion-current measurements is investigated. Molecular dynamics simulations and density functional theory calculations show that the metallacage spans the entire phospholipid bilayer as an unimolecular ion transport channel. This channel transports chloride ions across the cell membrane, which disturbs the ion balance of cancer cells and inhibits the growth of cancer cells at low concentrations.
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Affiliation(s)
- Qing-Hui Ling
- State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Yuanyuan Fu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200062, China
| | - Zhen-Chen Lou
- State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Bangkun Yue
- Key Laboratory of Micro-Nano Optoelectronic Devices (Wenzhou), College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou, 325035, China
| | - Chenxing Guo
- College of Chemistry and Environmental Engineering, Shenzhen University, Guangdong, 518055, China
| | - Xinyu Hu
- Key Laboratory of Micro-Nano Optoelectronic Devices (Wenzhou), College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou, 325035, China
| | - Weiqiang Lu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, 200062, China
| | - Lianrui Hu
- State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Wei Wang
- State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Min Zhang
- State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Hai-Bo Yang
- State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
| | - Lin Xu
- State Key Laboratory of Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China
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4
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Orfali R, Alwatban AZ, Orfali RS, Lau L, Chea N, Alotaibi AM, Nam YW, Zhang M. Oxidative stress and ion channels in neurodegenerative diseases. Front Physiol 2024; 15:1320086. [PMID: 38348223 PMCID: PMC10859863 DOI: 10.3389/fphys.2024.1320086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/12/2024] [Indexed: 02/15/2024] Open
Abstract
Numerous neurodegenerative diseases result from altered ion channel function and mutations. The intracellular redox status can significantly alter the gating characteristics of ion channels. Abundant neurodegenerative diseases associated with oxidative stress have been documented, including Parkinson's, Alzheimer's, spinocerebellar ataxia, amyotrophic lateral sclerosis, and Huntington's disease. Reactive oxygen and nitrogen species compounds trigger posttranslational alterations that target specific sites within the subunits responsible for channel assembly. These alterations include the adjustment of cysteine residues through redox reactions induced by reactive oxygen species (ROS), nitration, and S-nitrosylation assisted by nitric oxide of tyrosine residues through peroxynitrite. Several ion channels have been directly investigated for their functional responses to oxidizing agents and oxidative stress. This review primarily explores the relationship and potential links between oxidative stress and ion channels in neurodegenerative conditions, such as cerebellar ataxias and Parkinson's disease. The potential correlation between oxidative stress and ion channels could hold promise for developing innovative therapies for common neurodegenerative diseases.
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Affiliation(s)
- Razan Orfali
- Neuroscience Research Department, Research Centre, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Adnan Z. Alwatban
- Neuroscience Research Department, Research Centre, King Fahad Medical City, Riyadh, Saudi Arabia
| | | | - Liz Lau
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| | - Noble Chea
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| | - Abdullah M. Alotaibi
- Neuroscience Research Department, Research Centre, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Young-Woo Nam
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
| | - Miao Zhang
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
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5
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Rozario P, Pinilla M, Gorse L, Vind AC, Robinson KS, Toh GA, Firdaus MJ, Martínez JF, Kerk SK, Lin Z, Chambers JC, Bekker-Jensen S, Meunier E, Zhong F. Mechanistic basis for potassium efflux-driven activation of the human NLRP1 inflammasome. Proc Natl Acad Sci U S A 2024; 121:e2309579121. [PMID: 38175865 PMCID: PMC10786283 DOI: 10.1073/pnas.2309579121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 11/15/2023] [Indexed: 01/06/2024] Open
Abstract
Nigericin, an ionophore derived from Streptomyces hygroscopicus, is arguably the most commonly used tool compound to study the NLRP3 inflammasome. Recent findings, however, showed that nigericin also activates the NLRP1 inflammasome in human keratinocytes. In this study, we resolve the mechanistic basis of nigericin-driven NLRP1 inflammasome activation. In multiple nonhematopoietic cell types, nigericin rapidly and specifically inhibits the elongation stage of the ribosome cycle by depleting cytosolic potassium ions. This activates the ribotoxic stress response (RSR) sensor kinase ZAKα, p38, and JNK, as well as the hyperphosphorylation of the NLRP1 linker domain. As a result, nigericin-induced pyroptosis in human keratinocytes is blocked by extracellular potassium supplementation, ZAKα knockout, or pharmacologic inhibitors of ZAKα and p38 kinase activities. By surveying a panel of ionophores, we show that electroneutrality of ion movement is essential to activate ZAKα-driven RSR and a greater extent of K+ depletion is necessary to activate ZAKα-NLRP1 than NLRP3. These findings resolve the mechanism by which nigericin activates NLRP1 in nonhematopoietic cell types and demonstrate an unexpected connection between RSR, perturbations of potassium ion flux, and innate immunity.
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Affiliation(s)
- Pritisha Rozario
- Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore
| | - Miriam Pinilla
- Institute of Pharmacology and Structural Biology, University of Toulouse, CNRS, Toulouse31077, France
| | - Leana Gorse
- Institute of Pharmacology and Structural Biology, University of Toulouse, CNRS, Toulouse31077, France
| | - Anna Constance Vind
- Center for Healthy Aging, University of Copenhagen, Copenhagen2200, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen2200, Denmark
| | - Kim S. Robinson
- Agency for Science, Technology and Research (A*STAR) Skin Research Labs, 138648, Singapore
- Skin Research Institute of Singapore, 308232, Singapore
| | - Gee Ann Toh
- Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore
| | | | - José Francisco Martínez
- Center for Healthy Aging, University of Copenhagen, Copenhagen2200, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen2200, Denmark
| | - Swat Kim Kerk
- Population and Global Health Program, Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore
| | - Zhewang Lin
- Department of Biological Sciences, National University of Singapore, 117543, Singapore
| | - John C. Chambers
- Population and Global Health Program, Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore
| | - Simon Bekker-Jensen
- Center for Healthy Aging, University of Copenhagen, Copenhagen2200, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen2200, Denmark
| | - Etienne Meunier
- Institute of Pharmacology and Structural Biology, University of Toulouse, CNRS, Toulouse31077, France
| | - Franklin Zhong
- Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore
- Skin Research Institute of Singapore, 308232, Singapore
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6
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Sun J, Kulandaisamy A, Liu J, Hu K, Gromiha MM, Zhang Y. Machine learning in computational modelling of membrane protein sequences and structures: From methodologies to applications. Comput Struct Biotechnol J 2023; 21:1205-1226. [PMID: 36817959 PMCID: PMC9932300 DOI: 10.1016/j.csbj.2023.01.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/16/2023] [Accepted: 01/25/2023] [Indexed: 01/29/2023] Open
Abstract
Membrane proteins mediate a wide spectrum of biological processes, such as signal transduction and cell communication. Due to the arduous and costly nature inherent to the experimental process, membrane proteins have long been devoid of well-resolved atomic-level tertiary structures and, consequently, the understanding of their functional roles underlying a multitude of life activities has been hampered. Currently, computational tools dedicated to furthering the structure-function understanding are primarily focused on utilizing intelligent algorithms to address a variety of site-wise prediction problems (e.g., topology and interaction sites), but are scattered across different computing sources. Moreover, the recent advent of deep learning techniques has immensely expedited the development of computational tools for membrane protein-related prediction problems. Given the growing number of applications optimized particularly by manifold deep neural networks, we herein provide a review on the current status of computational strategies mainly in membrane protein type classification, topology identification, interaction site detection, and pathogenic effect prediction. Meanwhile, we provide an overview of how the entire prediction process proceeds, including database collection, data pre-processing, feature extraction, and method selection. This review is expected to be useful for developing more extendable computational tools specific to membrane proteins.
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Affiliation(s)
- Jianfeng Sun
- Botnar Research Centre, Nuffield Department of Orthopedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Headington, Oxford OX3 7LD, UK
| | - Arulsamy Kulandaisamy
- Department of Biotechnology, Bhupat and Jyoti Mehta School of BioSciences, Indian Institute of Technology Madras, Chennai 600 036, Tamilnadu, India
| | - Jacklyn Liu
- UCL Cancer Institute, University College London, 72 Huntley Street, London WC1E 6BT, UK
| | - Kai Hu
- Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education, Xiangtan University, Xiangtan 411105, China
| | - M. Michael Gromiha
- Department of Biotechnology, Bhupat and Jyoti Mehta School of BioSciences, Indian Institute of Technology Madras, Chennai 600 036, Tamilnadu, India,Corresponding authors.
| | - Yuan Zhang
- Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education, Xiangtan University, Xiangtan 411105, China,Corresponding authors.
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7
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Emerging mechanisms involving brain Kv7 channel in the pathogenesis of hypertension. Biochem Pharmacol 2022; 206:115318. [PMID: 36283445 DOI: 10.1016/j.bcp.2022.115318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022]
Abstract
Hypertension is a prevalent health problem inducing many organ damages. The pathogenesis of hypertension involves a complex integration of different organ systems including the brain. The elevated sympathetic nerve activity is closely related to the etiology of hypertension. Ion channels are critical regulators of neuronal excitability. Several mechanisms have been proposed to contribute to hypothalamic-driven elevated sympathetic activity, including altered ion channel function. Recent findings indicate one of the voltage-gated potassium channels, Kv7 channels (M channels), plays a vital role in regulating cardiovascular-related neurons activity, and the expression of Kv7 channels is downregulated in hypertension. This review highlights recent findings that the Kv7 channels in the brain, blood vessels, and kidneys are emerging targets involved in the pathogenesis of hypertension, suggesting new therapeutic targets for treating drug-resistant, neurogenic hypertension.
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8
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Teliska LH, Dalla Costa I, Sert O, Twiss JL, Rasband MN. Axon Initial Segments Are Required for Efficient Motor Neuron Axon Regeneration and Functional Recovery of Synapses. J Neurosci 2022; 42:8054-8065. [PMID: 36096668 PMCID: PMC9636994 DOI: 10.1523/jneurosci.1261-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/02/2022] [Indexed: 11/21/2022] Open
Abstract
The axon initial segment (AIS) generates action potentials and maintains neuronal polarity by regulating the differential trafficking and distribution of proteins, transport vesicles, and organelles. Injury and disease can disrupt the AIS, and the subsequent loss of clustered ion channels and polarity mechanisms may alter neuronal excitability and function. However, the impact of AIS disruption on axon regeneration after injury is unknown. We generated male and female mice with AIS-deficient multipolar motor neurons by deleting AnkyrinG, the master scaffolding protein required for AIS assembly and maintenance. We found that after nerve crush, neuromuscular junction reinnervation was significantly delayed in AIS-deficient motor neurons compared with control mice. In contrast, loss of AnkyrinG from pseudo-unipolar sensory neurons did not impair axon regeneration into the intraepidermal nerve fiber layer. Even after AIS-deficient motor neurons reinnervated the neuromuscular junction, they failed to functionally recover because of reduced synaptic vesicle protein 2 at presynaptic terminals. In addition, mRNA trafficking was disrupted in AIS-deficient axons. Our results show that, after nerve injury, an intact AIS is essential for efficient regeneration and functional recovery of axons in multipolar motor neurons. Our results also suggest that loss of polarity in AIS-deficient motor neurons impairs the delivery of axonal proteins, mRNAs, and other cargoes necessary for regeneration. Thus, therapeutic strategies for axon regeneration must consider preservation or reassembly of the AIS.SIGNIFICANCE STATEMENT Disruption of the axon initial segment is a common event after nervous system injury. For multipolar motor neurons, we show that axon initial segments are essential for axon regeneration and functional recovery after injury. Our results may help explain injuries where axon regeneration fails, and suggest strategies to promote more efficient axon regeneration.
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Affiliation(s)
- Lindsay H Teliska
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Irene Dalla Costa
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208
| | - Ozlem Sert
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
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9
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Naffaa MM, Al-Ewaidat OA. Ligand modulation of KCNQ-encoded (K V7) potassium channels in the heart and nervous system. Eur J Pharmacol 2021; 906:174278. [PMID: 34174270 DOI: 10.1016/j.ejphar.2021.174278] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/06/2021] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
KCNQ-encoded (KV7) potassium channels are diversely distributed in the human tissues, associated with many physiological processes and pathophysiological conditions. These channels are increasingly used as drug targets for treating diseases. More selective and potent molecules on various types of the KV7 channels are desirable for appropriate therapies. The recent knowledge of the structure and function of human KCNQ-encoded channels makes it more feasible to achieve these goals. This review discusses the role and mechanism of action of many molecules in modulating the function of the KCNQ-encoded potassium channels in the heart and nervous system. The effects of these compounds on KV7 channels help to understand their involvement in many diseases, and to search for more selective and potent ligands to be used in the treatment of many disorders such as various types of cardiac arrhythmias, epilepsy, and pain.
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Affiliation(s)
- Moawiah M Naffaa
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, 27710, USA; Department of Psychology and Neuroscience, Duke University, Durham, NC 27708, USA.
| | - Ola A Al-Ewaidat
- Faculty of Medicine, The University of Jordan, Amman, 11942, Jordan
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10
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Li N, Chen F, Shen J, Zhang H, Wang T, Ye R, Li T, Loh TP, Yang YY, Zeng H. Buckyball-Based Spherical Display of Crown Ethers for De Novo Custom Design of Ion Transport Selectivity. J Am Chem Soc 2020; 142:21082-21090. [PMID: 33274928 DOI: 10.1021/jacs.0c09655] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Searching for membrane-active synthetic analogues that are structurally simple yet functionally comparable to natural channel proteins has been of central research interest in the past four decades, yet custom design of the ion transport selectivity still remains a grand challenge. Here we report on a suite of buckyball-based molecular balls (MBs), enabling transmembrane ion transport selectivity to be custom designable. The modularly tunable MBm-Cn (m = 4-7; n = 6-12) structures consist of a C60-fullerene core, flexible alkyl linkers Cn (i.e., C6 for n-C6H12 group), and peripherally aligned benzo-3m-crown-m ethers (i.e., m = 4 for benzo-12-crown-4) as ion-transporting units. Screening a matrix of 16 such MBs, combinatorially derived from four different crown units and four different Cn linkers, intriguingly revealed that their transport selectivity well resembles the intrinsic ion binding affinity of the respective benzo-crown units present, making custom design of the transport selectivity possible. Specifically, MB4s, containing benzo-12-crown-4 units, all are Li+-selective in transmembrane ion transport, with the most active MB4-C10 exhibiting an EC50(Li+) value of 0.13 μM (corresponding to 0.13 mol % of the lipid present) while excluding all other monovalent alkali-metal ions. Likewise, the most Na+ selective MB5-C8 and K+ selective MB6-C8 demonstrate high Na+/K+ and K+/Na+ selectivity values of 13.7 and 7.8, respectively. For selectivity to Rb+ and Cs+ ions, the most active MB7-C8 displays exceptionally high transport efficiencies, with an EC50(Rb+) value of 105 nM (0.11 mol %) and an EC50(Cs+) value of 77 nM (0.079 mol %).
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Affiliation(s)
- Ning Li
- The NanoBio Lab, 31 Biopolis Way, The Nanos, Singapore 138669
| | - Feng Chen
- The NanoBio Lab, 31 Biopolis Way, The Nanos, Singapore 138669
| | - Jie Shen
- The NanoBio Lab, 31 Biopolis Way, The Nanos, Singapore 138669
| | - Hao Zhang
- Institute of Advanced Synthesis, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.,Yangtze River Delta Research Institute, Northwestern Polytechnical University, Taicang, Jiangsu 215400, People's Republic of China
| | - Tianxiang Wang
- School of Physical & Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Ruijuan Ye
- Institute of Advanced Synthesis, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.,Yangtze River Delta Research Institute, Northwestern Polytechnical University, Taicang, Jiangsu 215400, People's Republic of China
| | - Tianhu Li
- Institute of Advanced Synthesis, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.,Yangtze River Delta Research Institute, Northwestern Polytechnical University, Taicang, Jiangsu 215400, People's Republic of China
| | - Teck Peng Loh
- Institute of Advanced Synthesis, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.,Yangtze River Delta Research Institute, Northwestern Polytechnical University, Taicang, Jiangsu 215400, People's Republic of China.,School of Physical & Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Yi Yan Yang
- Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, #07-01, The Nanos, Singapore 138669
| | - Huaqiang Zeng
- Institute of Advanced Synthesis, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.,Yangtze River Delta Research Institute, Northwestern Polytechnical University, Taicang, Jiangsu 215400, People's Republic of China
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11
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Koźmiński W, Pera J. Involvement of the Peripheral Nervous System in Episodic Ataxias. Biomedicines 2020; 8:biomedicines8110448. [PMID: 33105744 PMCID: PMC7690566 DOI: 10.3390/biomedicines8110448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/04/2022] Open
Abstract
Episodic ataxias comprise a group of inherited disorders, which have a common hallmark—transient attacks of ataxia. The genetic background is heterogeneous and the causative genes are not always identified. Furthermore, the clinical presentation, including intraictal and interictal symptoms, as well as the retention and progression of neurological deficits, is heterogeneous. Spells of ataxia can be accompanied by other symptoms—mostly from the central nervous system. However, in some of episodic ataxias involvement of peripheral nervous system is a part of typical clinical picture. This review intends to provide an insight into involvement of peripheral nervous system in episodic ataxias.
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Affiliation(s)
- Wojciech Koźmiński
- Department of Neurology, University Hospital, ul. Jakubowskiego 2, 30-688 Krakow, Poland;
| | - Joanna Pera
- Department of Neurology, Jagiellonian University Medical College, ul. Botaniczna 3, 31-503 Krakow, Poland
- Correspondence:
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Ko EA, Kim YW, Lee D, Choi J, Kim S, Seo Y, Bang H, Kim JH, Ko JH. Expression of potassium channel genes predicts clinical outcome in lung cancer. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2019; 23:529-537. [PMID: 31680775 PMCID: PMC6819903 DOI: 10.4196/kjpp.2019.23.6.529] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/02/2019] [Accepted: 10/02/2019] [Indexed: 12/26/2022]
Abstract
Lung cancer is the most common cause of cancer deaths worldwide and several molecular signatures have been developed to predict survival in lung cancer. Increasing evidence suggests that proliferation and migration to promote tumor growth are associated with dysregulated ion channel expression. In this study, by analyzing high-throughput gene expression data, we identify the differentially expressed K+ channel genes in lung cancer. In total, we prioritize ten dysregulated K+ channel genes (5 up-regulated and 5 down-regulated genes, which were designated as K-10) in lung tumor tissue compared with normal tissue. A risk scoring system combined with the K-10 signature accurately predicts clinical outcome in lung cancer, which is independent of standard clinical and pathological prognostic factors including patient age, lymph node involvement, tumor size, and tumor grade. We further indicate that the K-10 potentially predicts clinical outcome in breast and colon cancers. Molecular signature discovered through K+ gene expression profiling may serve as a novel biomarker to assess the risk in lung cancer.
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Affiliation(s)
- Eun-A Ko
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada 89557, USA
| | - Young-Won Kim
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, Korea
| | - Donghee Lee
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, Korea
| | - Jeongyoon Choi
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, Korea
| | - Seongtae Kim
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, Korea
| | - Yelim Seo
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, Korea
| | - Hyoweon Bang
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, Korea
| | - Jung-Ha Kim
- Department of Family Medicine, Chung-Ang University Hospital, College of Medicine, Chung-Ang University, Seoul 06973, Korea
| | - Jae-Hong Ko
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, Korea
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13
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Sahu S, Zwolak M. Colloquium: Ionic phenomena in nanoscale pores through 2D materials. REVIEWS OF MODERN PHYSICS 2019; 91:10.1103/RevModPhys.91.021004. [PMID: 31579274 PMCID: PMC6774369 DOI: 10.1103/revmodphys.91.021004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Ion transport through nanopores permeates through many areas of science and technology, from cell behavior to sensing and separation to catalysis and batteries. Two-dimensional materials, such as graphene, molybdenum disulfide (MoS2), and hexagonal boron nitride (hBN), are recent additions to these fields. Low-dimensional materials present new opportunities to develop filtration, sensing, and power technologies, encompassing ion exclusion membranes, DNA sequencing, single molecule detection, osmotic power generation, and beyond. Moreover, the physics of ionic transport through pores and constrictions within these materials is a distinct realm of competing many-particle interactions (e.g., solvation/dehydration, electrostatic blockade, hydrogen bond dynamics) and confinement. This opens up alternative routes to creating biomimetic pores and may even give analogues of quantum phenomena, such as quantized conductance, in the classical domain. These prospects make membranes of 2D materials - i.e., 2D membranes - fascinating. We will discuss the physics and applications of ionic transport through nanopores in 2D membranes.
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Affiliation(s)
- Subin Sahu
- Biophysics Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Maryland NanoCenter, University of Maryland, College Park, Maryland 20742, USA
| | - Michael Zwolak
- Biophysics Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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14
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Moriguchi K, Miyamoto K, Fukumoto Y, Kusunoki S. 4-Aminopyridine ameliorates relapsing remitting experimental autoimmune encephalomyelitis in SJL/J mice. J Neuroimmunol 2018; 323:131-135. [PMID: 30139717 DOI: 10.1016/j.jneuroim.2018.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 07/30/2018] [Accepted: 08/16/2018] [Indexed: 02/07/2023]
Abstract
We evaluated the effects of a non-specific potassium channel blocker, 4-aminopyridine (4-AP), on chronic experimental autoimmune encephalomyelitis (chEAE) and relapsing remitting EAE (rrEAE) in mice. 4-AP did not affect chEAE, but ameliorated rrEAE, particularly in the relapsing phase. Disease amelioration was confirmed pathologically, and glial fibrillary acidic protein expression was observed to be downregulated in 4-AP-treated mice. In the recall response, a T-cell proliferative response was not inhibited; however, Th1/Th17 polarization was attenuated. 4-AP is currently accepted as an anti-symptomatic drug only in the chronic phase of multiple sclerosis (MS); however, its use in the active phase of MS should be considered.
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Affiliation(s)
- Kota Moriguchi
- Department of Neurology, Kindai University School of Medicine, Osaka-Sayama, Japan; Department of Internal Medicine, Japan Self Defense Forces Hanshin Hospital, Kawanishi, Japan; Division of Neurology, Department of Internal Medicine 3, National Defense Medical College, Tokorozawa, Japan
| | - Katsuichi Miyamoto
- Department of Neurology, Kindai University School of Medicine, Osaka-Sayama, Japan.
| | - Yuta Fukumoto
- Department of Neurology, Kindai University School of Medicine, Osaka-Sayama, Japan
| | - Susumu Kusunoki
- Department of Neurology, Kindai University School of Medicine, Osaka-Sayama, Japan
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15
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Kshatri AS, Gonzalez-Hernandez A, Giraldez T. Physiological Roles and Therapeutic Potential of Ca 2+ Activated Potassium Channels in the Nervous System. Front Mol Neurosci 2018; 11:258. [PMID: 30104956 PMCID: PMC6077210 DOI: 10.3389/fnmol.2018.00258] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/06/2018] [Indexed: 12/21/2022] Open
Abstract
Within the potassium ion channel family, calcium activated potassium (KCa) channels are unique in their ability to couple intracellular Ca2+ signals to membrane potential variations. KCa channels are diversely distributed throughout the central nervous system and play fundamental roles ranging from regulating neuronal excitability to controlling neurotransmitter release. The physiological versatility of KCa channels is enhanced by alternative splicing and co-assembly with auxiliary subunits, leading to fundamental differences in distribution, subunit composition and pharmacological profiles. Thus, understanding specific KCa channels’ mechanisms in neuronal function is challenging. Based on their single channel conductance, KCa channels are divided into three subtypes: small (SK, 4–14 pS), intermediate (IK, 32–39 pS) and big potassium (BK, 200–300 pS) channels. This review describes the biophysical characteristics of these KCa channels, as well as their physiological roles and pathological implications. In addition, we also discuss the current pharmacological strategies and challenges to target KCa channels for the treatment of various neurological and psychiatric disorders.
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Affiliation(s)
- Aravind S Kshatri
- Department of Basic Medical Sciences, Medical School, Universidad de La Laguna, Tenerife, Spain.,Instituto de Tecnologias Biomedicas, Universidad de La Laguna, Tenerife, Spain
| | - Alberto Gonzalez-Hernandez
- Department of Basic Medical Sciences, Medical School, Universidad de La Laguna, Tenerife, Spain.,Instituto de Tecnologias Biomedicas, Universidad de La Laguna, Tenerife, Spain
| | - Teresa Giraldez
- Department of Basic Medical Sciences, Medical School, Universidad de La Laguna, Tenerife, Spain.,Instituto de Tecnologias Biomedicas, Universidad de La Laguna, Tenerife, Spain
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16
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Gao X, Hwang TC. Spatial positioning of CFTR's pore-lining residues affirms an asymmetrical contribution of transmembrane segments to the anion permeation pathway. J Gen Physiol 2017; 147:407-22. [PMID: 27114613 PMCID: PMC4845689 DOI: 10.1085/jgp.201511557] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/28/2016] [Indexed: 12/22/2022] Open
Abstract
CFTR is a chloride channel and a member of the ABC transporter superfamily; however, its structure is unknown. By making a series of cysteine mutants, Gao and Hwang show that CFTR lacks the twofold pseudo-symmetry seen in the permeation pathway of bone fide ABC transporters. The structural composition of CFTR’s anion permeation pathway has been proposed to consist of a short narrow region, flanked by two wide inner and outer vestibules, based on systematic cysteine scanning studies using thiol-reactive probes of various sizes. Although these studies identified several of the transmembrane segments (TMs) as pore lining, the exact spatial relationship between pore-lining elements remains under debate. Here, we introduce cysteine pairs in several key pore-lining positions in TM1, 6, and 12 and use Cd2+ as a probe to gauge the spatial relationship of these residues within the pore. We find that inhibition of single cysteine CFTR mutants, such as 102C in TM1 or 341C in TM6, by intracellular Cd2+ is readily reversible upon removal of the metal ion. However, the inhibitory effect of Cd2+ on the double mutant 102C/341C requires the chelating agent dithiothreitol (DTT) for rapid reversal, indicating that 102C and 341C are close enough to the internal edge of the narrow region to coordinate one Cd2+ ion between them. We observe similar effects of extracellular Cd2+ on TM1/TM6 cysteine pairs 106C/337C, 107C/337C, and 107C/338C, corroborating the idea that these paired residues are physically close to each other at the external edge of the narrow region. Although these data paint a picture of relatively symmetrical contributions to CFTR’s pore by TM1 and TM6, introducing cysteine pairs between TM6 and TM12 (348C/1141C, 348C/1144C, and 348C/1145C) or between TM1 and TM12 (95C/1141C) yields results that contest the long-held principle of twofold pseudo-symmetry in the assembly of ABC transporters’ TMs. Collectively, these findings not only advance our current understanding of the architecture of CFTR’s pore, but could serve as a guide for refining computational models of CFTR by imposing physical constraints among pore-lining residues.
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Affiliation(s)
- Xiaolong Gao
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65211 Department of Biological Engineering, University of Missouri, Columbia, MO 65211
| | - Tzyh-Chang Hwang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65211 Department of Biological Engineering, University of Missouri, Columbia, MO 65211 Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO 65211
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17
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Bae YS, Yoon SH, Han JY, Woo J, Cho YS, Kwon SK, Bae YC, Kim D, Kim E, Kim MH. Deficiency of aminopeptidase P1 causes behavioral hyperactivity, cognitive deficits, and hippocampal neurodegeneration. GENES BRAIN AND BEHAVIOR 2017; 17:126-138. [PMID: 28834604 DOI: 10.1111/gbb.12419] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/14/2017] [Accepted: 08/21/2017] [Indexed: 12/14/2022]
Abstract
Metabolic diseases affect various organs including the brain. Accumulation or depletion of substrates frequently leads to brain injury and dysfunction. Deficiency of aminopeptidase P1, a cytosolic proline-specific peptidase encoded by the Xpnpep1 gene, causes an inborn error of metabolism (IEM) characterized by peptiduria in humans. We previously reported that knockout of aminopeptidase P1 in mice causes neurodevelopmental disorders and peptiduria. However, little is known about the pathophysiological role of aminopeptidase P1 in the brain. Here, we show that loss of aminopeptidase P1 causes behavioral and neurological deficits in mice. Mice deficient in aminopeptidase P1 (Xpnpep1-/- ) display abnormally enhanced locomotor activities in both the home cage and open-field box. The aminopeptidase P1 deficiency in mice also resulted in severe impairments in novel-object recognition, the Morris water maze task, and contextual, but not cued, fear memory. These behavioral dysfunctions were accompanied by epileptiform electroencephalogram activity and neurodegeneration in the hippocampus. However, mice with a heterozygous mutation for aminopeptidase P1 (Xpnpep1+/- ) exhibited normal behaviors and brain structure. These results suggest that loss of aminopeptidase P1 leads to behavioral, cognitive and neurological deficits. This study may provide insight into new pathogenic mechanisms for brain dysfunction related to IEMs.
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Affiliation(s)
- Y-S Bae
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - S H Yoon
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - J Y Han
- Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, Korea
| | - J Woo
- Department of Biological Sciences, KAIST, Daejeon, Korea
| | - Y S Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - S-K Kwon
- Department of Biological Sciences, KAIST, Daejeon, Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - Y C Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - D Kim
- Department of Biological Sciences, KAIST, Daejeon, Korea
| | - E Kim
- Department of Biological Sciences, KAIST, Daejeon, Korea.,Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon, Korea
| | - M-H Kim
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea.,Neuroscience Research Institute, Seoul National University Medical Research Center, Seoul, Korea.,Seoul National University Bundang Hospital, Seongnam, Gyeonggi, Korea
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18
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Genetically epilepsy-prone rats (GEPRs) and DBA/2 mice: Two animal models of audiogenic reflex epilepsy for the evaluation of new generation AEDs. Epilepsy Behav 2017; 71:165-173. [PMID: 26254980 DOI: 10.1016/j.yebeh.2015.06.030] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/12/2015] [Accepted: 06/17/2015] [Indexed: 01/08/2023]
Abstract
This review summarizes the current knowledge about DBA/2 mice and genetically epilepsy-prone rats (GEPRs) and discusses the contribution of such animal models on the investigation of possible new therapeutic targets and new anticonvulsant compounds for the treatment of epilepsy. Also, possible chemical or physical agents acting as proconvulsant agents are described. Abnormal activities of enzymes involved in catecholamine and serotonin synthesis and metabolism were reported in these models, and as a result of all these abnormalities, seizure susceptibility in both animals is greatly affected by pharmacological manipulations of the brain levels of monoamines and, prevalently, serotonin. In addition, both genetic epileptic models permit the evaluation of pharmacodynamic and pharmacokinetic interactions among several drugs measuring plasma and/or brain level of each compound. Audiogenic models of epilepsy have been used not only for reflex epilepsy studies, but also as animal models of epileptogenesis. The seizure predisposition (epileptiform response to sound stimulation) and substantial characterization of behavioral, cellular, and molecular alterations in both acute and chronic (kindling) protocols potentiate the usefulness of these models in elucidating ictogenesis, epileptogenesis, and their mechanisms. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".
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19
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Shock Wave-Induced Damage of a Protein by Void Collapse. Biophys J 2016; 110:147-56. [PMID: 26745418 DOI: 10.1016/j.bpj.2015.11.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 10/28/2015] [Accepted: 11/17/2015] [Indexed: 12/20/2022] Open
Abstract
In this study, we report on a series of molecular dynamics simulations that were used to examine the effects of shock waves on a membrane-bound ion channel. A planar shock wave was found to compress the ion channel upon impact, but the protein geometry resembles the crystal structure as soon as the solvent density begins to dissipate. When a void was placed in close proximity to the membrane, the shock wave proved to be more destructive to the protein due to formation of a nanojet that results from the asymmetric collapse of the void. The nanojet was able to cause significant structural changes to the protein even at low piston velocities that are not able to directly cause poration of the membrane.
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20
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Boss J, Liedvogel M, Lundberg M, Olsson P, Reischke N, Naurin S, Åkesson S, Hasselquist D, Wright A, Grahn M, Bensch S. Gene expression in the brain of a migratory songbird during breeding and migration. MOVEMENT ECOLOGY 2016; 4:4. [PMID: 26881054 PMCID: PMC4753645 DOI: 10.1186/s40462-016-0069-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/28/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND We still have limited knowledge about the underlying genetic mechanisms that enable migrating species of birds to navigate the globe. Here we make an attempt to get insight into the genetic architecture controlling this complex innate behaviour. We contrast the gene expression profiles of two closely related songbird subspecies with divergent migratory phenotypes. In addition to comparing differences in migratory strategy we include a temporal component and contrast patterns between breeding adults and autumn migrating juvenile birds of both subspecies. The two willow warbler subspecies, Phylloscopus trochilus trochilus and P. t. acredula, are remarkably similar both in phenotype and genotype and have a narrow contact zone in central Scandinavia. Here we used a microarray gene chip representing 23,136 expressed sequence tags (ESTs) from the zebra finch Taeniopygia guttata to identify mRNA level differences in willow warbler brain tissue in relation to subspecies and season. RESULTS Out of the 22,109 EST probe sets that remained after filtering poorly binding probes, we found 11,898 (51.8 %) probe sets that could be reliably and uniquely matched to a total of 6,758 orthologous zebra finch genes. The two subspecies showed very similar levels of gene expression with less than 0.1 % of the probe sets being significantly differentially expressed. In contrast, 3,045 (13.8 %) probe sets were found to be differently regulated between samples collected from breeding adults and autumn migrating juvenile birds. The genes found to be differentially expressed between seasons appeared to be enriched for functional roles in neuronal firing and neuronal synapse formation. CONCLUSIONS Our results show that only few genes are differentially expressed between the subspecies. This suggests that the different migration strategies of the subspecies might be governed by few genes, or that the expression patterns of those genes are time-structured or tissue-specific in ways, which our approach fails to uncover. Our findings will be useful in the planning of new experiments designed to unravel the genes involved in the migratory program of birds.
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Affiliation(s)
- John Boss
- />Karolinska Institute, Department of Laboratory Medicine, Clinical Research Center, Karolinska University Hospital, SE-14186 Huddinge, Sweden
- />School of Natural Sciences, Technology and Environmental Studies, Södertörn University, SE-141 89 Huddinge, Sweden
| | - Miriam Liedvogel
- />Department of Biology, Molecular Ecology and Evolution Laboratory, Lund University, Ecology Building, SE-22362 Lund, Sweden
- />Max Planck Institute for Evolutionary Biology, AG Behavioural Genomics, August-Thienemann-Straße 2, 24306 Plön, Germany
| | - Max Lundberg
- />Department of Biology, Molecular Ecology and Evolution Laboratory, Lund University, Ecology Building, SE-22362 Lund, Sweden
| | - Peter Olsson
- />Centre of Environmental and Climate Research, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Nils Reischke
- />Department of Biology, Molecular Ecology and Evolution Laboratory, Lund University, Ecology Building, SE-22362 Lund, Sweden
| | - Sara Naurin
- />Department of Biology, Molecular Ecology and Evolution Laboratory, Lund University, Ecology Building, SE-22362 Lund, Sweden
| | - Susanne Åkesson
- />Department of Biology, Centre for Animal Movement Research, Lund University, Ecology Building, SE-22362 Lund, Sweden
| | - Dennis Hasselquist
- />Department of Biology, Molecular Ecology and Evolution Laboratory, Lund University, Ecology Building, SE-22362 Lund, Sweden
| | - Anthony Wright
- />Karolinska Institute, Department of Laboratory Medicine, Clinical Research Center, Karolinska University Hospital, SE-14186 Huddinge, Sweden
| | - Mats Grahn
- />Karolinska Institute, Department of Laboratory Medicine, Clinical Research Center, Karolinska University Hospital, SE-14186 Huddinge, Sweden
| | - Staffan Bensch
- />Department of Biology, Molecular Ecology and Evolution Laboratory, Lund University, Ecology Building, SE-22362 Lund, Sweden
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21
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Kumar P, Kumar D, Jha SK, Jha NK, Ambasta RK. Ion Channels in Neurological Disorders. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:97-136. [DOI: 10.1016/bs.apcsb.2015.10.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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22
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Lin CH, Yang CT, Tsai MC, Wu YT, MacDonald I, Wang ML, Wu CH, Leung YM, Chen YH. (±)3,4-Methylenedioxyamphetamine inhibits the TEA-sensitive K+ current in the hippocampal neuron and the Kv2.1 current expressed in H1355 cells. Neuropharmacology 2015; 89:100-12. [DOI: 10.1016/j.neuropharm.2014.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 08/20/2014] [Accepted: 09/04/2014] [Indexed: 10/24/2022]
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The evolution of pentameric ligand-gated ion-channels and the changing family of anthelmintic drug targets. Parasitology 2014; 142:303-17. [PMID: 25354656 DOI: 10.1017/s003118201400170x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
SUMMARY Pentameric ligand-gated ion-channels rapidly transduce synaptic neurotransmitter signals to an electrical response in post-synaptic neuronal or muscle cells and control the neuromusculature of a majority of multicellular animals. A wide range of pharmaceuticals target these receptors including ethanol, nicotine, anti-depressants and other mood regulating drugs, compounds that control pain and mobility and are targeted by a majority of anthelmintic drugs used to control parasitic infection of humans and livestock. Major advances have been made in recent years to our understanding of the structure, function, activity and the profile of compounds that can activate specific receptors. It is becoming clear that these anthelmintic drug targets are not fixed, but differ in significant details from one nematode species to another. Here we review what is known about the evolution of the pentameric ligand-gated ion-channels, paying particular attention to the nematodes, how we can infer the origins of such receptors and understand the factors that determine how they change both over time and from one species to another. Using this knowledge provides a biological framework in which to understand these important drug targets and avenues to identify new receptors and aid the search for new anthelmintic drugs.
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24
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Ge L, Hoa NT, Wilson Z, Arismendi-Morillo G, Kong XT, Tajhya RB, Beeton C, Jadus MR. Big Potassium (BK) ion channels in biology, disease and possible targets for cancer immunotherapy. Int Immunopharmacol 2014; 22:427-43. [PMID: 25027630 PMCID: PMC5472047 DOI: 10.1016/j.intimp.2014.06.040] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 06/27/2014] [Accepted: 06/30/2014] [Indexed: 11/18/2022]
Abstract
The Big Potassium (BK) ion channel is commonly known by a variety of names (Maxi-K, KCNMA1, slo, stretch-activated potassium channel, KCa1.1). Each name reflects a different physical property displayed by this single ion channel. This transmembrane channel is found on nearly every cell type of the body and has its own distinctive roles for that tissue type. The BKα channel contains the pore that releases potassium ions from intracellular stores. This ion channel is found on the cell membrane, endoplasmic reticulum, Golgi and mitochondria. Complex splicing pathways produce different isoforms. The BKα channels can be phosphorylated, palmitoylated and myristylated. BK is composed of a homo-tetramer that interacts with β and γ chains. These accessory proteins provide a further modulating effect on the functions of BKα channels. BK channels play important roles in cell division and migration. In this review, we will focus on the biology of the BK channel, especially its role, and its immune response towards cancer. Recent proteomic studies have linked BK channels with various proteins. Some of these interactions offer further insight into the role that BK channels have with cancers, especially with brain tumors. This review shows that BK channels have a complex interplay with intracellular components of cancer cells and still have plenty of secrets to be discovered.
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Affiliation(s)
- Lisheng Ge
- Research Service, VA Long Beach Healthcare System, 5901 E. 7th Street, Long Beach, CA 90822, USA
| | - Neil T Hoa
- Research Service, VA Long Beach Healthcare System, 5901 E. 7th Street, Long Beach, CA 90822, USA
| | - Zechariah Wilson
- Research Service, VA Long Beach Healthcare System, 5901 E. 7th Street, Long Beach, CA 90822, USA
| | | | - Xiao-Tang Kong
- Department of Neuro-Surgery, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Rajeev B Tajhya
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christine Beeton
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Martin R Jadus
- Research Service, VA Long Beach Healthcare System, 5901 E. 7th Street, Long Beach, CA 90822, USA; Pathology and Laboratory Medicine Service, VA Long Beach Healthcare System, 5901 E. 7th Street, Long Beach, CA 90822, USA; Neuro-Oncology Program, Chao Comprehensive Cancer Center, University of California, Irvine, Orange, CA 92868, USA; Pathology and Laboratory Medicine, Med Sci I, University of California, Irvine, CA 92697, USA.
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Battle KN, Jackson JM, Witek MA, Hupert ML, Hunsucker SA, Armistead PM, Soper SA. Solid-phase extraction and purification of membrane proteins using a UV-modified PMMA microfluidic bioaffinity μSPE device. Analyst 2014; 139:1355-63. [PMID: 24487280 PMCID: PMC3970079 DOI: 10.1039/c3an02400h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We present a novel microfluidic solid-phase extraction (μSPE) device for the affinity enrichment of biotinylated membrane proteins from whole cell lysates. The device offers features that address challenges currently associated with the extraction and purification of membrane proteins from whole cell lysates, including the ability to release the enriched membrane protein fraction from the extraction surface so that they are available for downstream processing. The extraction bed was fabricated in PMMA using hot embossing and was comprised of 3600 micropillars. Activation of the PMMA micropillars by UV/O3 treatment permitted generation of surface-confined carboxylic acid groups and the covalent attachment of NeutrAvidin onto the μSPE device surfaces, which was used to affinity select biotinylated MCF-7 membrane proteins directly from whole cell lysates. The inclusion of a disulfide linker within the biotin moiety permitted release of the isolated membrane proteins via DTT incubation. Very low levels (∼20 fmol) of membrane proteins could be isolated and recovered with ∼89% efficiency with a bed capacity of 1.7 pmol. Western blotting indicated no traces of cytosolic proteins in the membrane protein fraction as compared to significant contamination using a commercial detergent-based method. We highlight future avenues for enhanced extraction efficiency and increased dynamic range of the μSPE device using computational simulations of different micropillar geometries to guide future device designs.
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Affiliation(s)
- Katrina N. Battle
- Department of Chemistry, Louisiana State University, 232 Choppin Hall, Baton Rouge, LA 70803-1804, USA
| | - Joshua M. Jackson
- Department of Chemistry, University of North Carolina, Campus Box 3290, Chapel Hill, NC 27599-3290, USA
| | - Małgorzata A. Witek
- Department of Biomedical Engineering, University of North Carolina,152 MacNider Hall Campus Box 7575 Chapel Hill, NC 27599-7575, USA
| | - Mateusz L. Hupert
- Department of Biomedical Engineering, University of North Carolina,152 MacNider Hall Campus Box 7575 Chapel Hill, NC 27599-7575, USA
- BioFluidica, LLC, c/o Carolina Kick-Start, 321 Bondurant Hall, Chapel Hill, NC, 27599
| | - Sally A. Hunsucker
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Paul M. Armistead
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Steven A. Soper
- Department of Chemistry, University of North Carolina, Campus Box 3290, Chapel Hill, NC 27599-3290, USA
- Department of Biomedical Engineering, University of North Carolina,152 MacNider Hall Campus Box 7575 Chapel Hill, NC 27599-7575, USA
- BioFluidica, LLC, c/o Carolina Kick-Start, 321 Bondurant Hall, Chapel Hill, NC, 27599
- School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
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Abstract
Ion channels are integral membrane proteins that allow the flow of ions across membranes down their electrochemical gradients and are a major determinant of cellular excitability. They play an important role in a variety of biological processes as diverse as insulin release from beta cells in the pancreas through to cardiac and smooth muscle contraction. We have used total internal reflection fluorescence (TIRF) microscopy to watch ion channels being transported in vesicles along microtubules within the cytoplasm of the cell. Furthermore, we can directly observe the fusion of these vesicles with the plasma membrane and the release and radial dispersion of single ion channels into the membrane. Finally, automated single-particle tracking of these objects allowed us to determine their diffusional behavior.
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Drumm BR, Bourke B, Drummond J, McNicholas F, Quinn S, Broderick A, Taaffe S, Twomey J, Rowland M. Cyclical vomiting syndrome in children: a prospective study. Neurogastroenterol Motil 2012; 24:922-7. [PMID: 22762244 DOI: 10.1111/j.1365-2982.2012.01960.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Cyclical vomiting syndrome (CVS) is a disorder that affects all ages and is characterized by episodes of severe nausea and vomiting with symptom-free intervals between episodes. The incidence in children is 3.15/100 000 children per year. Our objective was to evaluate the natural history of CVS and examine factors that predict symptom resolution. METHODS Thirty newly diagnosed children (mean 9.15 years, SD 3.31 range 3.5-15.7) were enrolled. All children had a follow-up interview at 3 months, 27/30 at 6 months, and 22/30 at 9 months. KEY RESULTS Following diagnosis of CVS, only 5/22(22.7%) children had no further episodes of vomiting at 9 months, whereas 17/22 (77.3%) continued to vomit. In the year prior to diagnosis, 15/30 (50%) children were admitted to hospital. Of the 22 children with follow-up for 9 months, only one child required hospital admission. Children who continued to vomit had higher internalizing scores on CBCL compared with those who stopped vomiting (P = NS). The Pediatric Quality-of-Life Score suggested those who continued to vomit had a poorer quality of life at diagnosis compared with those who stopped vomiting (P < 0.05). CONCLUSIONS & INFERENCES Making a positive diagnosis of CVS and providing families with information is very important in the management of CVS. Although 75% of children reported regular episodes of vomiting 9 months after diagnosis, there was a significant reduction in the frequency and severity of symptoms in addition to a marked reduction in the use of medical services.
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Affiliation(s)
- B R Drumm
- UCD School of Medicine and Medical Sciences, Dublin Academic Medical Centre, Dublin 7, Ireland
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Coordinated signal integration at the M-type potassium channel upon muscarinic stimulation. EMBO J 2012; 31:3147-56. [PMID: 22643219 DOI: 10.1038/emboj.2012.156] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 04/25/2012] [Indexed: 01/08/2023] Open
Abstract
Several neurotransmitters, including acetylcholine, regulate neuronal tone by suppressing a non-inactivating low-threshold voltage-gated potassium current generated by the M-channel. Agonist dependent control of the M-channel is mediated by calmodulin, activation of anchored protein kinase C (PKC), and depletion of the phospholipid messenger phosphatidylinositol 4,5-bisphosphate (PIP2). In this report, we show how this trio of second messenger responsive events acts synergistically and in a stepwise manner to suppress activity of the M-current. PKC phosphorylation of the KCNQ2 channel subunit induces dissociation of calmodulin from the M-channel complex. The calmodulin-deficient channel has a reduced affinity towards PIP2. This pathway enhances the effect of concomitant reduction of PIP2, which leads to disruption of the M-channel function. These findings clarify how a common lipid cofactor, such as PIP2, can selectively regulate ion channels.
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Ye S, Li H, Wei F, Jasensky J, Boughton AP, Yang P, Chen Z. Observing a model ion channel gating action in model cell membranes in real time in situ: membrane potential change induced alamethicin orientation change. J Am Chem Soc 2012; 134:6237-43. [PMID: 22420296 PMCID: PMC3328217 DOI: 10.1021/ja2110784] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ion channels play crucial roles in transport and regulatory functions of living cells. Understanding the gating mechanisms of these channels is important to understanding and treating diseases that have been linked to ion channels. One potential model peptide for studying the mechanism of ion channel gating is alamethicin, which adopts a split α/3(10)-helix structure and responds to changes in electric potential. In this study, sum frequency generation vibrational spectroscopy (SFG-VS), supplemented by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), has been applied to characterize interactions between alamethicin (a model for larger channel proteins) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid bilayers in the presence of an electric potential across the membrane. The membrane potential difference was controlled by changing the pH of the solution in contact with the bilayer and was measured using fluorescence spectroscopy. The orientation angle of alamethicin in POPC lipid bilayers was then determined at different pH values using polarized SFG amide I spectra. Assuming that all molecules adopt the same orientation (a δ distribution), at pH = 6.7 the α-helix at the N-terminus and the 3(10)-helix at the C-terminus tilt at about 72° (θ(1)) and 50° (θ(2)) versus the surface normal, respectively. When pH increases to 11.9, θ(1) and θ(2) decrease to 56.5° and 45°, respectively. The δ distribution assumption was verified using a combination of SFG and ATR-FTIR measurements, which showed a quite narrow distribution in the angle of θ(1) for both pH conditions. This indicates that all alamethicin molecules at the surface adopt a nearly identical orientation in POPC lipid bilayers. The localized pH change in proximity to the bilayer modulates the membrane potential and thus induces a decrease in both the tilt and the bend angles of the two helices in alamethicin. This is the first reported application of SFG to the study of model ion channel gating mechanisms in model cell membranes.
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Affiliation(s)
- Shuji Ye
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, P.R.China 230026
| | - Hongchun Li
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, P.R.China 230026
| | - Feng Wei
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, P.R.China 230026
| | - Joshua Jasensky
- Department of Biophysics, University of Michigan, AnnArbor, MI 48109, USA
| | - Andrew P. Boughton
- Department of Chemistry, University of Michigan, AnnArbor, MI 48109, USA
| | - Pei Yang
- Department of Chemistry, University of Michigan, AnnArbor, MI 48109, USA
| | - Zhan Chen
- Department of Biophysics, University of Michigan, AnnArbor, MI 48109, USA
- Department of Chemistry, University of Michigan, AnnArbor, MI 48109, USA
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Abstract
Cell surface proteins play a very important role in physiology and pathology and are receiving increased attention by the pharmaceutical industry as valuable targets for development of new therapeutics. However, owing to the very nature of this category of proteins, their comprehensive study remains an elusive task. A number of methods have been proposed to enrich and purify cell surface proteins. Among them, usage of biotinylating reagents and exploitation of the strong interaction between biotin and streptavidin for the purification of biotinylated proteins has rapidly gained in popularity and allowed some of the most significant progresses in quantitative proteomics. This chapter focuses on methods for cell surface biotinylation with commercially available reagents, capture by avidin-affinity chromatography and release of the biotinylated surface proteins for downstream analysis by electrophoretic techniques.
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Sausbier U, Dullin C, Missbach-Guentner J, Kabagema C, Flockerzie K, Kuscher GM, Stuehmer W, Neuhuber W, Ruth P, Alves F, Sausbier M. Osteopenia due to enhanced cathepsin K release by BK channel ablation in osteoclasts. PLoS One 2011; 6:e21168. [PMID: 21695131 PMCID: PMC3114853 DOI: 10.1371/journal.pone.0021168] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 05/23/2011] [Indexed: 01/05/2023] Open
Abstract
Background The process of bone resorption by osteoclasts is regulated by Cathepsin K, the lysosomal collagenase responsible for the degradation of the organic bone matrix during bone remodeling. Recently, Cathepsin K was regarded as a potential target for therapeutic intervention of osteoporosis. However, mechanisms leading to osteopenia, which is much more common in young female population and often appears to be the clinical pre-stage of idiopathic osteoporosis, still remain to be elucidated, and molecular targets need to be identified. Methodology/Principal Findings We found, that in juvenile bone the large conductance, voltage and Ca2+-activated (BK) K+ channel, which links membrane depolarization and local increases in cytosolic calcium to hyperpolarizing K+ outward currents, is exclusively expressed in osteoclasts. In juvenile BK-deficient (BK−/−) female mice, plasma Cathepsin K levels were elevated two-fold when compared to wild-type littermates. This increase was linked to an osteopenic phenotype with reduced bone mineral density in long bones and enhanced porosity of trabecular meshwork in BK−/− vertebrae as demonstrated by high-resolution flat-panel volume computed tomography and micro-CT. However, plasma levels of sRANKL, osteoprotegerin, estrogene, Ca2+ and triiodthyronine as well as osteoclastogenesis were not altered in BK−/− females. Conclusion/Significance Our findings suggest that the BK channel controls resorptive osteoclast activity by regulating Cathepsin K release. Targeted deletion of BK channel in mice resulted in an osteoclast-autonomous osteopenia, becoming apparent in juvenile females. Thus, the BK−/− mouse-line represents a new model for juvenile osteopenia, and revealed the BK channel as putative new target for therapeutic controlling of osteoclast activity.
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Affiliation(s)
- Ulrike Sausbier
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Christian Dullin
- Department of Diagnostic Radiology, University Medical Center Göttingen, Göttingen, Germany
| | | | - Clement Kabagema
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Katarina Flockerzie
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Gerd Marten Kuscher
- Max-Planck-Institute for Experimental Medicine, Department of Molecular Biology of Neuronal Signals, Göttingen, Germany
| | - Walter Stuehmer
- Max-Planck-Institute for Experimental Medicine, Department of Molecular Biology of Neuronal Signals, Göttingen, Germany
| | - Winfried Neuhuber
- Institute for Anatomy, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Peter Ruth
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Frauke Alves
- Max-Planck-Institute for Experimental Medicine, Department of Molecular Biology of Neuronal Signals, Göttingen, Germany
- Department of Hematology and Oncology, University Medical Center Göttingen, Göttingen, Germany
| | - Matthias Sausbier
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
- * E-mail:
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Xing TR, Yong W, Chen L, Tang ML, Wang M, Chen JT, Ruan DY. Effects of decabrominated diphenyl ether (PBDE 209) on voltage-gated sodium channels in primary cultured rat hippocampal neurons. ENVIRONMENTAL TOXICOLOGY 2010; 25:400-408. [PMID: 19526529 DOI: 10.1002/tox.20511] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are widely used as flame-retardant additives. But the application of PBDEs has been challenged due to their toxicity, especially neurotoxicity. In this study, we investigated the effects of decabrominated diphenyl ether (PBDE 209), the major PBDEs product, on voltage-gated sodium channels (VGSCs) in primary cultured rat hippocampal neurons. Employing the whole-cell patch-clamp technique, we found that PBDE 209 could irreversibly decrease voltage-gated sodium channel currents (I(Na)) in a very low dose and in a concentration-dependent manner. We had systematically explored the effects of PBDE 209 on I(Na) and found that PBDE 209 could shift the activation and inactivation of I(Na) toward hyperpolarizing direction, slow down the recovery from inactivation of I(Na), and decrease the fraction of activated sodium channels. These results suggested that PBDE 209 could affect VGSCs, which may lead to changes in electrical activities and contribute to neurotoxicological damages. We also showed that ascorbic acid, as an antioxidant, was able to mitigate the inhibitory effects of PBDE 209 on VGSCs, which suggested that PBDE 209 might inhibit I(Na) through peroxidation. Our findings provide new insights into the mechanism for the neurological symptoms caused by PBDE 209.
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Affiliation(s)
- Tai-Ran Xing
- Department of Neuroscience and Biophysics, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China
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Warren WC, Clayton DF, Ellegren H, Arnold AP, Hillier LW, Künstner A, Searle S, White S, Vilella AJ, Fairley S, Heger A, Kong L, Ponting CP, Jarvis ED, Mello CV, Minx P, Lovell P, Velho TAF, Ferris M, Balakrishnan CN, Sinha S, Blatti C, London SE, Li Y, Lin YC, George J, Sweedler J, Southey B, Gunaratne P, Watson M, Nam K, Backström N, Smeds L, Nabholz B, Itoh Y, Whitney O, Pfenning AR, Howard J, Völker M, Skinner BM, Griffin DK, Ye L, McLaren WM, Flicek P, Quesada V, Velasco G, Lopez-Otin C, Puente XS, Olender T, Lancet D, Smit AFA, Hubley R, Konkel MK, Walker JA, Batzer MA, Gu W, Pollock DD, Chen L, Cheng Z, Eichler EE, Stapley J, Slate J, Ekblom R, Birkhead T, Burke T, Burt D, Scharff C, Adam I, Richard H, Sultan M, Soldatov A, Lehrach H, Edwards SV, Yang SP, Li X, Graves T, Fulton L, Nelson J, Chinwalla A, Hou S, Mardis ER, Wilson RK. The genome of a songbird. Nature 2010; 464:757-62. [PMID: 20360741 PMCID: PMC3187626 DOI: 10.1038/nature08819] [Citation(s) in RCA: 614] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 01/06/2010] [Indexed: 01/16/2023]
Abstract
The zebra finch is an important model organism in several fields with unique relevance to human neuroscience. Like other songbirds, the zebra finch communicates through learned vocalizations, an ability otherwise documented only in humans and a few other animals and lacking in the chicken-the only bird with a sequenced genome until now. Here we present a structural, functional and comparative analysis of the genome sequence of the zebra finch (Taeniopygia guttata), which is a songbird belonging to the large avian order Passeriformes. We find that the overall structures of the genomes are similar in zebra finch and chicken, but they differ in many intrachromosomal rearrangements, lineage-specific gene family expansions, the number of long-terminal-repeat-based retrotransposons, and mechanisms of sex chromosome dosage compensation. We show that song behaviour engages gene regulatory networks in the zebra finch brain, altering the expression of long non-coding RNAs, microRNAs, transcription factors and their targets. We also show evidence for rapid molecular evolution in the songbird lineage of genes that are regulated during song experience. These results indicate an active involvement of the genome in neural processes underlying vocal communication and identify potential genetic substrates for the evolution and regulation of this behaviour.
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Affiliation(s)
- Wesley C Warren
- The Genome Center, Washington University School of Medicine, Campus Box 8501, 4444 Forest Park Avenue, St Louis, Missouri 63108, USA.
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Ye S, Nguyen KT, Chen Z. Interactions of alamethicin with model cell membranes investigated using sum frequency generation vibrational spectroscopy in real time in situ. J Phys Chem B 2010; 114:3334-40. [PMID: 20163089 PMCID: PMC2844632 DOI: 10.1021/jp911174d] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Structures of membrane-associated peptides and molecular interactions between peptides and cell membrane bilayers govern biological functions of these peptides. Sum frequency generation (SFG) vibrational spectroscopy has been demonstrated to be a powerful technique to study such structures and interactions at the molecular level. In this research, SFG has been applied, supplemented by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), to characterize the interactions between alamethicin (a model for larger channel proteins) and different lipid bilayers in the absence of membrane potential. The orientation of alamethicin in lipid bilayers has been determined using SFG amide I spectra detected with different polarization combinations. It was found that alamethicin adopts a mixed alpha-helical and 3(10)-helical structure in fluid-phase lipid bilayers. The helix (mainly alpha-helix) at the N-terminus tilts at about 63 degrees versus the surface normal in a fluid-phase 1,2-dimyristoyl-d54-sn-glycero-3-phosphocholine-1,1,2,2-d4-N,N,N-trimethyl-d9 (d-DMPC)/1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayer. The 3(10)-helix at the C-terminus (beyond the Pro14 residue) tilts at about 43 degrees versus the surface normal. This is the first time to apply SFG to study a 3(10)-helix experimentally. When interacting with a gel-phase lipid bilayer, alamethicin lies down on the gel-phase bilayer surface or aggregates or both, which does not have significant insertion into the lipid bilayer.
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Affiliation(s)
- Shuji Ye
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui, P.R. China 230026
| | - Khoi Tan Nguyen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
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Down-regulation of delayed rectifier K+ channels in the hippocampus of seizure sensitive gerbils. Brain Res Bull 2009; 80:433-42. [PMID: 19665528 DOI: 10.1016/j.brainresbull.2009.07.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 06/22/2009] [Accepted: 07/29/2009] [Indexed: 01/23/2023]
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Ji L, Chauhan A, Brown WT, Chauhan V. Increased activities of Na+/K+-ATPase and Ca2+/Mg2+-ATPase in the frontal cortex and cerebellum of autistic individuals. Life Sci 2009; 85:788-93. [PMID: 19863947 DOI: 10.1016/j.lfs.2009.10.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 09/17/2009] [Accepted: 10/15/2009] [Indexed: 01/31/2023]
Abstract
AIMS Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase are enzymes known to maintain intracellular gradients of ions that are essential for signal transduction. The aim of this study was to compare the activities of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase in postmortem brain samples from the cerebellum and frontal, temporal, parietal, and occipital cortices from autistic and age-matched control subjects. MAIN METHODS The frozen postmortem tissues from different brain regions of autistic and control subjects were homogenized. The activities of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase were assessed in the brain homogenates by measuring inorganic phosphorus released by the action of Na(+)/K(+)- and Ca(2+)/Mg(2+)-dependent hydrolysis of ATP. KEY FINDINGS In the cerebellum, the activities of both Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase were significantly increased in the autistic samples compared with their age-matched controls. The activity of Na(+)/K(+)-ATPase but not Ca(2+)/Mg(2+)-ATPase was also significantly increased in the frontal cortex of the autistic samples as compared to the age-matched controls. In contrast, in other regions, i.e., the temporal, parietal and occipital cortices, the activities of these enzymes were similar in autism and control groups. SIGNIFICANCE The results of this study suggest brain-region specific increases in the activities of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase in autism. Increased activity of these enzymes in the frontal cortex and cerebellum may be due to compensatory responses to increased intracellular calcium concentration in autism. We suggest that altered activities of these enzymes may contribute to abnormal neuronal circuit functioning in autism.
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Affiliation(s)
- Lina Ji
- NYS Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, New York 10314, USA
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Barbado M, Fablet K, Ronjat M, De Waard M. Gene regulation by voltage-dependent calcium channels. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1096-104. [PMID: 19250948 DOI: 10.1016/j.bbamcr.2009.02.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 02/13/2009] [Accepted: 02/16/2009] [Indexed: 12/11/2022]
Abstract
Ca2+ is the most widely used second messenger in cell biology and fulfills a plethora of essential cell functions. One of the most exciting findings of the last decades was the involvement of Ca2+ in the regulation of long-term cell adaptation through its ability to control gene expression. This finding provided a link between cell excitation and gene expression. In this review, we chose to focus on the role of voltage-dependent calcium channels in mediating gene expression in response to membrane depolarization. We illustrate the different pathways by which these channels are involved in excitation-transcription coupling, including the most recent Ca2+ ion-independent strategies that highlight the transcription factor role of calcium channels.
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Affiliation(s)
- Maud Barbado
- Grenoble Institute of Neuroscience, Inserm U 836-Team 3 Calcium Channels, Functions and Pathologies, Bâtiment Edmond Safra, Université Joseph Fourier, Site santé de la Tronche, BP 170, 38042 Grenoble cedex 9, France
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Roy S, Mitra I, Llinas R. Non-Markovian noise mediated through anomalous diffusion within ion channels. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:041920. [PMID: 18999468 DOI: 10.1103/physreve.78.041920] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Indexed: 05/27/2023]
Abstract
It is evident from a wide range of experimental findings that ion channel gating is inherently stochastic. The issue of "memory effects" (diffusional retardation due to local changes in water viscosity) in ionic flow has been recently addressed using Brownian dynamics simulations. The results presented indicate such memory effects are negligible, unless the diffusional barrier is much higher than that of free solute. In this paper using differential stochastic methods we conclude that the Markovian property of exponential dwell times gives rise to a high barrier, resulting in diffusional memory effects that cannot be ignored in determining ionic flow through channels. We have addressed this question using a generalized Langevin equation that contains a combination of Markovian and non-Markovian processes with different time scales. This approach afforded the development of an algorithm that describes an oscillatory ionic diffusional sequence. The resulting oscillatory function behavior, with exponential decay, was obtained at the weak non-Markovian limit with two distinct time scales corresponding to the processes of ionic diffusion and drift. This will be analyzed further in future studies using molecular dynamics simulations. We propose that the rise of time scales and memory effects is related to differences of shear viscosity in the cytoplasm and extracellular matrix.
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Affiliation(s)
- Sisir Roy
- Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700108, India.
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Yan D, Wang L, Ma FL, Deng H, Liu J, Li C, Wang H, Chen J, Tang JL, Ruan DY. Developmental exposure to lead causes inherent changes on voltage-gated sodium channels in rat hippocampal CA1 neurons. Neuroscience 2008; 153:436-45. [DOI: 10.1016/j.neuroscience.2008.02.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2007] [Revised: 01/20/2008] [Accepted: 02/14/2008] [Indexed: 12/29/2022]
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Abstract
Cardiac ion channels are surprisingly dynamic in nature, and are continuously formed, trafficked to specific subregions of plasma membrane, inserted in the plasma membrane, and removed to be degraded or recycled. Because of these movements, which affect channel availability, ion channel function is dependent on not just channel biophysical properties but channel trafficking as well. The development of molecular techniques to tag proteins of interest with fluorescent and other genetically encoded proteins, and of advanced imaging modalities such as total internal reflection microscopy (TIRF), have created new opportunities to understand the intracellular movement of proteins near the plasma membrane and their dynamics therein. In this article we present approaches for ion channel biologists to the use of fluorescent and nonfluorescent fusion proteins, techniques for cloning and expression of fusion proteins in mammalian cells, and imaging techniques for live-cell high-resolution microscopy. For illustration, original data are presented on creation of a stable cell line capable of inducible expression of connexin 43 tagged to green fluorescent protein and its distribution viewed with both wide-field epifluorescence and TIRF microscopy. With revolutionary advances in fluorescence microscopy, ion channel biologists are now entering a new realm of studying channel function, which is to understand the mechanisms of channel trafficking.
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Affiliation(s)
- James W Smyth
- Cardiovascular Research Institute and Department of Medicine, University of California San Francisco, San Francisco, California, USA
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41
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Kurosu M, Katayama S, Shibuya H, Kitagawa I. A study of the calcium complex of a glucosylceramide, soya-cerebroside II. Chem Pharm Bull (Tokyo) 2008; 55:1758-61. [PMID: 18057755 DOI: 10.1248/cpb.55.1758] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In order to study calcium ion complex of soya-cerebroside II (1), an ionophoretic glucosylceramide isolated from soybean, C8-cerebroside (3) and 3,3'',6''-trideoxy-C8-cerebroside (4) are designed and synthesized. On the basis of extensive 1H-NMR studies in the presence of Ca2+ and a continuous variation method via (1)H-NMR, soya-cerebroside II is suggested to form a calcium complex with 1/Ca2+ ratio of 1 : 1. Soya-cerebroside II serves as a tridentate chelating ligand for Ca2+; the amide carbonyl, C2'-hydroxy, and C2''-hydroxy oxygens are responsible for the Ca2+ binding. Soya-cerebroside II is structurally analogous to a neural glucosylceramide. Thus, the accumulated neural glucosylceramide inside of endoplasmic reticulum (ER) membrane may serve as an endogenous Ca2+-binding and -transport molecule (ionophore) that result in mobilization of Ca2+ from intracellular calcium stores.
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Affiliation(s)
- Michio Kurosu
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 1682 Campus Delivery, Fort Coliins, CO 80523-1682, USA.
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42
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Kelkar DA, Chattopadhyay A. The gramicidin ion channel: A model membrane protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:2011-25. [PMID: 17572379 DOI: 10.1016/j.bbamem.2007.05.011] [Citation(s) in RCA: 264] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Revised: 05/09/2007] [Accepted: 05/10/2007] [Indexed: 02/07/2023]
Abstract
The linear peptide gramicidin forms prototypical ion channels specific for monovalent cations and has been extensively used to study the organization, dynamics and function of membrane-spanning channels. In recent times, the availability of crystal structures of complex ion channels has challenged the role of gramicidin as a model membrane protein and ion channel. This review focuses on the suitability of gramicidin as a model membrane protein in general, and the information gained from gramicidin to understand lipid-protein interactions in particular. Special emphasis is given to the role and orientation of tryptophan residues in channel structure and function and recent spectroscopic approaches that have highlighted the organization and dynamics of the channel in membrane and membrane-mimetic media.
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Affiliation(s)
- Devaki A Kelkar
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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43
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Xiong Q, Sun H, Li M. Zinc pyrithione-mediated activation of voltage-gated KCNQ potassium channels rescues epileptogenic mutants. Nat Chem Biol 2007; 3:287-96. [PMID: 17435769 DOI: 10.1038/nchembio874] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Accepted: 03/20/2007] [Indexed: 11/09/2022]
Abstract
KCNQ potassium channels are activated by changes in transmembrane voltage and play an important role in controlling electrical excitability. Human mutations of KCNQ2 and KCNQ3 potassium channel genes result in reduction or loss of channel activity and cause benign familial neonatal convulsions (BFNCs). Thus, small molecules capable of augmenting KCNQ currents are essential both for understanding the mechanism of channel activity and for developing therapeutics. We performed a high-throughput screen in search for agonistic compounds potentiating KCNQ potassium channels. Here we report identification of a new opener, zinc pyrithione (1), which activates both recombinant and native KCNQ M currents. Interactions with the channel protein cause an increase of single-channel open probability that could fully account for the overall conductance increase. Separate point mutations have been identified that either shift the concentration dependence or affect potentiation efficacy, thereby providing evidence for residues influencing ligand binding and downstream events. Furthermore, zinc pyrithione is capable of rescuing the mutant channels causal to BFNCs.
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Affiliation(s)
- Qiaojie Xiong
- Department of Neuroscience, High Throughput Biology Center, School of Medicine, Johns Hopkins University, 733 North Broadway, Baltimore, Maryland 21205, USA
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44
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Freudenberg J, Fu YH, Ptácek LJ. Bioinformatic analysis of human CNS-expressed ion channels as candidates for episodic nervous system disorders. Neurogenetics 2007; 8:159-68. [PMID: 17333079 DOI: 10.1007/s10048-007-0082-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Accepted: 01/29/2007] [Indexed: 10/23/2022]
Abstract
As monogenic forms of episodic nervous system disorders are often caused by ion channel mutations, we looked for features of human central nervous system (CNS) expressed ion channels that further our understanding of those phenotypes. To this end, we compared human ion channels with other CNS-expressed genes, which we categorized according to the existence of transmembrane domains. When looking at the phylogenetic distribution of these genes, we observed an increased percentage of ion channels that exist in vertebrate genomes while missing in invertebrate genomes. Because we hypothesized that this pattern may relate to a more specific expression, we searched for characteristics of ion channels that indicate a tighter expression regulation. We found that ion channels have longer intron and protein sequences, features typical of genes with more specific expression. In addition, ion channels have increased human-rodent conservation around their transcription start site, as indicated by a higher fraction of conserved noncoding regions. This points to a high relevance of mutations that regulate ion channel expression. When we finally asked whether vertebrate-specific diversification is also displayed by non-ion channel genes with important roles in the CNS, we found a similar phylogenetic distribution. This concordant phylogenetic pattern suggests that vertebrate-specific adaptations may account for a large part of the shared genetic basis of episodic CNS disorders, including monogenic and genetically complex disease manifestations. Consequently, this phylogenetic pattern may contribute to the prioritization of candidate genes in human genetic studies of episodic CNS disorders.
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Affiliation(s)
- Jan Freudenberg
- Laboratories of Neurogenetics, Department of Neurology, Institute of Human Genetics, University of California San Francisco, San Francisco, CA 94158-2922, USA.
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45
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Shao HB, Jiang SY, Li FM, Chu LY, Zhao CX, Shao MA, Zhao XN, Li F. Some advances in plant stress physiology and their implications in the systems biology era. Colloids Surf B Biointerfaces 2007; 54:33-6. [PMID: 16814995 DOI: 10.1016/j.colsurfb.2006.05.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Revised: 05/01/2006] [Accepted: 05/21/2006] [Indexed: 02/06/2023]
Abstract
The study for biointerfaces at different scales in the past years has pricked up the march of biological sciences, in which biomembrane concept and its characteristics, receptor proteins, ion channel proteins, LEA proteins, calcium and newly recognized second messengers, ROS, MAPKs and their related sensors and new genes in osmoregulation, signal transduction, and other aspects have been understood fully, widening area of understanding the extensive interactions from biosystem and biointerfaces. The related discipline, plant stress physiology, especially, crop stress physiology has gained much attention world widely, the important reason of which is from the reducing quality of global ecoenvironment and decreasing food supply. This short review will place a stress on the recent progresses in plant stress physiology, combined with the new results from our State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau.
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Affiliation(s)
- Hong-Bo Shao
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Centre of Soil and Water Conservation and Eco-environmental Research, The Chinese Academy of Sciences, Northwest A&F University, Yangling 712100, China.
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46
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Cheng J, Gong Z, Zhu W, Tang Y, Li W, Li Z, Jiang H. Cation sitting in aromatic cages:ab initio computational studies on tetramethylammonium–(benzene)n (n=3–4) complexes. J PHYS ORG CHEM 2007. [DOI: 10.1002/poc.1175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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47
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Joho RH, Street C, Matsushita S, Knöpfel T. Behavioral motor dysfunction in Kv3-type potassium channel-deficient mice. GENES BRAIN AND BEHAVIOR 2006; 5:472-82. [PMID: 16923152 DOI: 10.1111/j.1601-183x.2005.00184.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The voltage-gated potassium channels Kv3.1 and Kv3.3 are expressed in several distinct neuronal subpopulations in brain areas known to be involved in motor control such as cortex, basal ganglia and cerebellum. Depending on the lack of Kv3.1 or Kv3.3 channel subunits, mutant mice show different Kv3-null allele-dependent behavioral alterations that include constitutive hyperactivity, sleep loss, impaired motor performance and, in the case of the Kv3.1/Kv3.3 double mutant, also severe ataxia, tremor and myoclonus (Espinosa et al. 2001, J Neurosci 21, 6657-6665, Genes, Brain Behav 3, 90-100). The lack of Kv3.1 channel subunits is mainly responsible for the constitutively increased locomotor activity and for sleep loss, whereas the absence of Kv3.3 subunits affects cerebellar function, in particular Purkinje cell discharges and olivocerebellar system properties (McMahon et al. 2004, Eur J Neurosci 19, 3317-3327). Here, we describe two sensitive and non-invasive tests to reliably quantify normal and abnormal motor functions, and we apply these tests to characterize motor dysfunction in Kv3-mutant mice. In contrast to wildtype and Kv3.1-single mutants, Kv3.3-single mutants and Kv3 mutants lacking three and four Kv3 alleles display Kv3-null allele-dependent gait alterations. Although the Kv3-null allele-dependent gait changes correlate with reduced motor performance, they appear to not affect the training-induced improvement of motor performance. These findings suggest that altered cerebellar physiology in the absence of Kv3.3 channels is responsible for impaired motor task execution but not motor task learning.
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Affiliation(s)
- R H Joho
- Center for Basic Neuroscience, The University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA.
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48
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Fureman BE, Hess EJ. Noradrenergic blockade prevents attacks in a model of episodic dysfunction caused by a channelopathy. Neurobiol Dis 2006; 20:227-32. [PMID: 16242631 DOI: 10.1016/j.nbd.2005.03.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Revised: 12/06/2004] [Accepted: 03/04/2005] [Indexed: 11/20/2022] Open
Abstract
Episodic neurological dysfunction often results from ion channel gene mutations. Despite knowledge of the mutations, the factors that precipitate attacks in channelopathies are not clear. In humans, mutations of the calcium channel gene CACNA1A are associated with attacks of neurological dysfunction in familial hemiplegic migraine and episodic ataxia type-2. In tottering mice, a mutation in the same gene causes attacks resembling paroxysmal dyskinesia. Stress, a trigger associated with human episodic disorders, reliably elicits attacks in tottering mice. Because noradrenergic neurotransmission is critical to the stress response and because noradrenergic hyperinnervation is observed in tottering mice, the role of norepinephrine in stress-induced attacks was investigated. Drugs that act at alpha-adrenergic receptors to block noradrenergic transmission prevented attacks. However, agents that facilitate noradrenergic neurotransmission failed to induce attacks. These results suggest that, while noradrenergic neurotransmission may be necessary for attacks, an increase in norepinephrine is not sufficient to induce attacks.
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MESH Headings
- Adrenergic Agonists/pharmacology
- Adrenergic alpha-Antagonists/pharmacology
- Animals
- Autonomic Nervous System Diseases/genetics
- Autonomic Nervous System Diseases/metabolism
- Autonomic Nervous System Diseases/physiopathology
- Brain/drug effects
- Brain/metabolism
- Brain/physiopathology
- Brain Diseases, Metabolic/drug therapy
- Brain Diseases, Metabolic/genetics
- Brain Diseases, Metabolic/physiopathology
- Calcium Channels/genetics
- Disease Models, Animal
- Female
- Ion Channels/drug effects
- Ion Channels/genetics
- Ion Channels/metabolism
- Male
- Mice
- Mice, Neurologic Mutants
- Movement Disorders/drug therapy
- Movement Disorders/physiopathology
- Movement Disorders/prevention & control
- Mutation/genetics
- Norepinephrine/antagonists & inhibitors
- Norepinephrine/metabolism
- Receptors, Adrenergic, alpha/drug effects
- Receptors, Adrenergic, alpha/metabolism
- Stress, Physiological/metabolism
- Stress, Physiological/physiopathology
- Synaptic Transmission/drug effects
- Synaptic Transmission/genetics
- Treatment Outcome
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Affiliation(s)
- Brandy E Fureman
- Department of Neurology, Johns Hopkins University, Baltimore, MD 21152, USA
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49
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Stevens MF, Golla E, Lipfert P. [Intraoperative and postoperative analgesia with a caudal catheter in a child suffering from Schwartz-Jampel syndrome]. Anaesthesist 2006; 55:555-60. [PMID: 16389541 DOI: 10.1007/s00101-005-0967-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The Schwartz-Jampel syndrome, also known as myotonia chondrodystrophica, is a rare autosomal recessive disorder characterized by bone dysplasia, growth retardation and generalized myotonia. Laryngoscopy and intubation may be difficult because of micrognathia and limited mouth opening due to myotonia of the masseter muscles. As regional anaesthesia reduces myotonic contractions and avoids administration of opioids causing respiratory depression, it appears to be the ideal method for postoperative analgesia. We report on a 5-year-old girl who underwent osteotomy of both hips and received intraoperative and postoperative analgesia via a caudal catheter. Excellent analgesia without myoclonic episodes could be achieved by continuous infusion of ropivacaine.
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Affiliation(s)
- M F Stevens
- Klinik für Anästhesiologie, Universitätsklinikum, Düsseldorf, Germany.
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50
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Sausbier U, Sausbier M, Sailer CA, Arntz C, Knaus HG, Neuhuber W, Ruth P. Ca2+ -activated K+ channels of the BK-type in the mouse brain. Histochem Cell Biol 2005; 125:725-41. [PMID: 16362320 DOI: 10.1007/s00418-005-0124-7] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2005] [Indexed: 10/25/2022]
Abstract
An antibody against the 442 carboxy-terminal amino acids of the BK channel alpha-subunit detects high immunoreactivity within the telencephalon in cerebral cortices, olfactory bulb, basal ganglia and hippocampus, while lower levels are found in basal forebrain regions and amygdala. Within the diencephalon, high density was found in nuclei of the ventral and dorsal thalamus and the medial habenular nucleus, and low density in the hypothalamus. The fasciculus retroflexus and its termination in the mesencephalic interpeduncular nucleus are prominently stained. Other mesencephalic expression sites are periaquaeductal gray and raphe nuclei. In the rhombencephalon, BK channels are enriched in the cerebellar cortex and in the locus coeruleus. Strong immunoreactivity is also contained in the vestibular nuclei, but not in cranial nerves and their intramedullary course of their roots. On the cellular level, BK channels show pre- and postsynaptic localizations, i.e., in somata, dendrites, axons and synaptic terminals.
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Affiliation(s)
- Ulrike Sausbier
- Pharmakologie und Toxikologie, Pharmazeutisches Institut der Universität Tübingen, Tübingen, Germany
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